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The Moon Motions. The Moon. Have you ever noticed that the moon looks different from night to night?. Have you ever noticed that some nights, there doesn’t appear to be a moon at all?.
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The Moon Have you ever noticed that the moon looks different from night to night? Have you ever noticed that some nights, there doesn’t appear to be a moon at all? By observing the Moon over a period of several weeks, one will notice that the Moon rises and sets at different times each night.
Why Does This Happen? The moon rotates on its axis and revolves around the Earth. One rotation and one revolution take the same amount of time, about 29 ½ days. Because of this, the same side of the moon always faces Earth.
Phases of the Moon The changes in how the moon looks to people on Earth are called the moon’s phases. Of course, the moon does not really change shape. What changes is the part of the moon that reflects light from the sun to Earth.
The Moon We See The shape of the part of the moon that reflects light to Earth depends on two things: – The moon’s position in its orbit around Earth. • The position of the sun. In every phase of the moon, the lit part faces the sun. Even if you cannot see the sun, you can tell where it is by how it lights the moon.
Moon Phases Every 29 ½ days, the same phase of the moon repeats. This is called a lunar cycle.
New Moon The phase of the moon occurring when it passes between the earth and the sun and is invisible or visible only as a narrow crescent at sunset.
Waxing Crescent At this moon phase, the Earth, moon and sun are located nearly on a line in space. Because the waxing crescent moon is nearly on a line with the Earth and sun, the “day side” is facing mostly away from us. We see only a slender fraction of the day side: a crescent moon.
First Quarter A first quarter moon looks like half a pie. It rises at noon and is high overhead at sunset. It sets around midnight. A first quarter moon is called “first quarter” because it is one quarter of the way around in its orbit of Earth.
Waxing Gibbous A waxing gibbous moon appears high in the east at sunset. It’s nearly, but not quite, a full moon . . . appearing more than half lighted but less than full. This moon phase comes between one and two weeks after new moon.
Full Moon A full moon always rises in the east around the time the sun is setting in the west. At full moon, we are seeing all of the moon’s day side. The moon and sun are on a line, with Earth in between. Full moon always comes about two weeks after new moon, when the moon is midway around in its orbit of Earth, as measured from one new moon to the next.
Waning Gibbous A waning gibbous moon sails over the eastern horizon in the hours between sunset and midnight. It’s past full now . . . appearing less than full but more than half lighted. In fact, in the few days after full moon, you’ll often see the waning gibbous moon in the west in early morning, floating against the pale blue sky.
Last Quarter The last quarter moon comes about three weeks after the new moon. The moon is now three-quarters of the way around in its orbit of Earth, as measured from one new moon to the next. A last quarter moon looks half-illuminated. It rises around midnight, appears at its highest in the sky at dawn, and sets around noon.
Waning Crescent A waning crescent moon—sometimes called an “old moon”—is seen in the east before dawn. Now the moon has moved nearly entirely around in its orbit of Earth. Because the moon is nearly on a line with the Earth and sun again, the “day side” of the moon is facing mostly away from us once more. We see only a slender fraction of the moon’s day side: a crescent moon.
In New York City on June 8, 2003, a full moon was shining in the night sky. Then, starting at about 6:00 P.M., a shadow began to creep across the moon’s surface. About two hours later, the shadow covered the entire moon.
What just happened? People in the city had just seen an eclipse of the moon. The eclipse was visible everywhere that it was night. An eclipse happens when one object in space casts a shadow on another object in space.
On that night in 2003, the Earth cast a shadow on the moon. Lunar Eclipse This type of eclipse occurs when Earth comes between the sun and the moon.
Do you know the other type of Eclipse? Solar Eclipse In a solar eclipse, the moon casts a shadow on Earth. People in this shadow see the sun slowly blotted out by the moon passing between it and Earth.
